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Class 8 Maths Worksheet: Squares and Square Roots

Maths worksheets lesson 58: Squares and square roots · Set 93 · 40 sums
TalentJR

The method (Pairs make squares): Square: n × n. Quick way: (a + b)² = a² + 2ab + b², e.g. 42² = 1600 + 160 + 4. Square root: the number that times itself gives the square; a square ending in 4 has a root ending in 2 or 8. Make a perfect square: break into primes; multiply (or divide) by the prime left without a partner. 1 + 3 + 5 + … (n odd numbers) = n². Between n² and (n + 1)² there are 2n whole numbers.

NameDateTime takenScore ___ / 40
  1. 1.What is √900? =
  2. 2.What is √3025? =
  3. 3.What is the sum of the first 11 odd numbers (1 + 3 + 5 + …)?
  4. 4.What is the smallest whole number by which 45 must be multiplied to get a perfect square?
  5. 5.What is the sum of the first 13 odd numbers (1 + 3 + 5 + …)?
  6. 6.A square garden has an area of 25 square m. How long is each side (in m)?
  7. 7.What is √2809? =
  8. 8.What is √9801? =
  9. 9.What is √6400? =
  10. 10.What is the smallest whole number by which 24 must be divided to get a perfect square?
  11. 11.A square garden has an area of 729 square m. How long is each side (in m)?
  12. 12.What is √1024? =
  13. 13.What is the smallest whole number by which 128 must be multiplied to get a perfect square?
  14. 14.How many whole numbers lie between 37² and 38²?
  15. 15.How many whole numbers lie between 42² and 43²?
  16. 16.A square garden has an area of 1521 square m. How long is each side (in m)?
  17. 17.Which of these is a perfect square? (a) 1156 (b) 1218 (c) 1161
  18. 18.What is the sum of the first 5 odd numbers (1 + 3 + 5 + …)?
  19. 19.A square garden has an area of 841 square m. How long is each side (in m)?
  20. 20.Which of these is a perfect square? (a) 938 (b) 900 (c) 903
  21. 21.How many whole numbers lie between 39² and 40²?
  22. 22.How many whole numbers lie between 10² and 11²?
  23. 23.What is the smallest whole number by which 162 must be multiplied to get a perfect square?
  24. 24.What is 92²? =
  25. 25.What is 72²? =
  26. 26.What is the smallest whole number by which 240 must be multiplied to get a perfect square?
  27. 27.What is the smallest whole number by which 150 must be multiplied to get a perfect square?
  28. 28.What is 35²? =
  29. 29.What is √324? =
  30. 30.Which of these is a perfect square? (a) 160 (b) 144 (c) 150
  31. 31.What is 16²? =
  32. 32.What is the sum of the first 22 odd numbers (1 + 3 + 5 + …)?
  33. 33.What is the sum of the first 12 odd numbers (1 + 3 + 5 + …)?
  34. 34.What is the smallest whole number by which 63 must be divided to get a perfect square?
  35. 35.What is the smallest whole number by which 52 must be divided to get a perfect square?
  36. 36.What is the sum of the first 6 odd numbers (1 + 3 + 5 + …)?
  37. 37.What is √289? =
  38. 38.What is the sum of the first 9 odd numbers (1 + 3 + 5 + …)?
  39. 39.What is √225? =
  40. 40.Which of these is a perfect square? (a) 729 (b) 743 (c) 741

Answer key

  1. 30
  2. 55
  3. 121
  4. 5
  5. 169
  6. 5
  7. 53
  8. 99
  9. 80
  10. 6
  11. 27
  12. 32
  13. 2
  14. 74
  15. 84
  16. 39
  17. 1156
  18. 25
  19. 29
  20. 900
  21. 78
  22. 20
  23. 2
  24. 8464
  25. 5184
  26. 15
  27. 6
  28. 1225
  29. 18
  30. 144
  31. 256
  32. 484
  33. 144
  34. 7
  35. 13
  36. 36
  37. 17
  38. 81
  39. 15
  40. 729

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